Method of purifying, concentrating, and converting petroleum sulfonates with ethers



Feb. 12, 1957 u. B. BRAY Y 2,781,316

METHOD OF PURnIF'YING, CONCENTRATING AND CONVERTING a PETROLEUMSULFONATES WITH ETHERS Flled July 12, 1954 '4-Sheets-Sheet 1 PQUDUCT Far ,Lr/5 Armin/evs.

Linee/5, Irv/04 F0579? a: @was VFeb. l2, 1957 BRAY 2,781,316

. U. B. METHOD 0F PURIFYING, CONCENTRATING AND CONVERTING PETROLEUMSULFONATES WITH ETHERS Filed July l2, 1954 I 4 Sheets-Sheet 2 Feb. 12,1957 u. B. BRAY 2,781,316 G, coNcENTRATmG AND couvER'rm 4 Sheets-Sheet 3METHOD 0F PURIFYIN PETROLEUM SULFONATES WITH -ETHERS Filed July 12, 1954www NSY wp; X

2,781,316 TING 4 Sheets$heet 4 Feb. 12, 1957 u. B. BRAY .V METHOD OFPURIFYING, CONCENTRATING AND CONVER PETROLEUM-SULFONATES WITH ETHERSFiled July 12. 1954 B @HSS Zil' Patented Feb. 12, i957 METHOD orrumoroso, CoNcnNrnAriNo,

AND coNvERTING irnrnoitnnrvi surro- NATEswirn ETHEns Ulric E. Bray,Pasadena; alif., assigner to Bray @il Company, Los Angeles, Calif., alimited partnership invention relates to the" purication andconcentration of hydrocarbon sulfonates of the oil-soluble or mahoganyacid type, and tothe conversion of these sulfonates to polyvalent metalsulfonates. This application is a continuation-in-part of my" earlierapplication Serial No. 167,798, tiled lune 13, 1950,issued as Patent No.2,689,221. l

ln the preparation of'some rust preventing compounds and lubricants, andin thepreparation of some lubricants for severe service uses and forsimilar lubricating uses, it has been a practice for many years toemploy various metaly salts ot` sulfonic acids derived from the reactionof sulfuric acid and petroleum fractions in the lubricating oil range.VThesesulfonic acids, and their salts are well known in the petroleumindustry. Those most commonly used for the present purpose are' theoil-soluble acids known as mahogany acids which are found in solution ina supernatant oil layer which accumulates above anV acid sludgelayerupon settling `cfa batch of petroleum lubricating Voil followingstrong sulfuricacid treatment. The sulfuric acid treatment of petroleumlubricating oil results also in the production of otherL sulfonic acids,known as green acids, which are primarily water-soluble and are,therefore, found chieiiy in the acid sludge layer. However,someofthese`water-soluble green acids are found in the Vpresence `o`fthe oil-soluble mahogany acids in Ythe oil layer and are (objectionablefOr, Certain purposes. Possibly` these vagrant water-soluble sulionicYacids pass in'to 'the oil layer because'they are at 'the same timeymoderately oil-soluble, or becausel they are to that exv tentsolubilized by the action of themahogany acids, or because of,thefailure to remove the last traces of pepper sludge from theacid-treated oil. As a result,

these objectionable water-soluble green acids are carried over assulfonate into'the oils-soluble sulfonate which is commonly placed uponthe market as the sodium salts of the mahogany acids.` jFor the purposeof preparing rust preventing compounds'and severe service lubricants,these sodiumfmahogany acid ,salts Vare commonly converted by met'athesis`into alkalineearth metal sulfonates, usually the calciumor'bariumsalts, The calcium Asalts of the true mahogany" acids appe'arfto,` bealmost entirely insoluble inV water although oil-soluble.But'stheresultant calcium salts ofthe green acids, which are readilywatersoluble, are apparently also` oil-soluble in theV presence ofmahogany .acid salt'. Because `of their water-solubility, they areobjectionable in rust preventivfes'and in lubricat ing oilswherefmoistur'e may be encountered, because they appearto weaken ,theresistance to water of an oil fihn on metal, lpossibly'through favoringthe formation of a wajter-contin`uous4 emulsion; whereas the Water-insoluble, oil-soluble calcium 'salts of vthe true mahogany acids, whenVoperating `in lthe presenceof 'waterto form emulsions, result inemulsionsjwhere oil is the continuous phase.` r` In the caseof'oil-continuous emulsions, oil preferentially wets iron or steelsurfaces with the result thatthe water' present `in the" emulsiony doesnot wet the metal' and'zrustingfis avoided. f On the'other, hand, wherethe chemical environment produces water-continuous emulsions, the waterphase displaces the oil from the metal surface, thereby reducing ordestroying the rust inhibiting eiect of the oil. Even though theoil-soluble, water-insoluble sulfonates greatly predominate, neverthe-`less, `appreciable proportions of water-soluble sulfonates result inundesirable effects` when the polyvalent-metal sulfonates are usedV asdetergent additives or rust preventives in lubricants. Forl example,even a relatively small proportion of the water-soluble sulfonateresults in excessive Water corrosion, to the extentpthart products failto give the full degree of protection required in severe service, suchas in military and naval operation.

it is an important object of the present, invention to purifyalkali-metal and ammonium mahogany sulfonates by ridding them of thementioned objectionable substances, to concentrate such mahoganysulfonates with respect tto oil by eliminatingexcess oil therefrom, andthen to convert to polyvalent-metal forms the mahogany sulfonates sopurified and concentrated in order that they may be useful incorresponding rust preventive and detergent lubricating oil.

Another object is to separate the green acid sulfonates and inorganicsulfates or other inorganicV salts which would forni insoluble saltswith calcium or other` polyvalent metal to be used, as water-solubleforms in a water and emulsion-breaking liquid layer from which the oiland water-soluble, alkali-metal and ammonium mahogany sulfonates presentare caused to separate.

it is also an object to provide a process for recovering oil-soluble,Water-insoluble, polyvalent-metal sulfonates, such as calcium mahoganysulfonates, in oil, whereby excess oil beyond that desired in a givenproduct is easily rejected in the presence of water and certainoil-soluble,v emulsion-breaking, organic liquids, such as certainketones, ethers and glycols. A particular object is to remove excess oilbefore conversion or the mahogany sulfonate to the water-insoluble,polyvalent-metal form.

it :is also an object to separate the objectionable inorganic saltsmentioned in a water-soluble tormwhereby to avoid the necessity ofsubsequently iiltering their insoluble forms from the oil-sulfonateproduct, and whereby to reduce employment of filter aid and the like andthe incidental costs thereof.

it is a still further object of the invention to provide a process forthe recovery of petroleum sulfonates whereby formation of diiiicultlybreaking emulsions, such as the large so-called cuff layers, is avoided.

Still another object of the invention is to provide a process for thetreatment of crudetpetroleum sulfonates containing excessively' largeVproportions of petroleum oil, appreciable amounts of water andobjectionable inorganic salts and green acid sulfonates, whereby theobjectionable materials and excess petroleum oil are easily eliminated.Y

Thus, individual objects are: to eliminate all green acid sulfonates; toeliminate all objectionable inorganic salts It is also an object topurify land/or concentratecrude alkali-magohany sulfonate for use asemulsifying and wetting agents or for other desired uses to whichsodium,

potassium and( or ammonium hydrocarbon sulfonates and Y sulfates may beput.

It is also an objectito provide a puriiication, concentra# as sodiumsulfate.

tion, and conversion process for crude sulfonates of the indicatedcharacter whereby very large batches of crude material of high oilcontent and relatively low sulfonate content may be so treated withrelative ease, as against treatment of only relatively small batches asheretofore.

Other objects of the invention will become apparent from the followingdescription, as will the various features of the invention. Inconnection with the following specification reference is made to theaccompanying drawings wherein:

Fig. l is a flow diagram representing the major steps of the processwhen operated batchwise;

Fig. 2 presents curves showing various relationships among variouscomponent materials present during the operation of the process;

Fig. 3 is a ow diagram representing the principal steps of the processwhen operated continuously in single or multiple stages; and

Fig. 4 is a flow diagram representing the principal steps of the processwhen operated countercurrently.

Throughout this specification, the terms water-soluble and oil-solubleare used to signify either partial or cornplete miscibility orsolubility in water and oil respectively. The term soap will sometimesbe used to signify the respective sulfonate. Where reference is made toremoval or elimination of green acid soaps or inorganic salts, suchterminology is intended to include either complete elimination orreduction of the respective materials to such insignificant proportionsthat the presence of the remainder does not interfere seriously withsubsequent processing or it is not detrimental for uses to which thesulfonate product is eventually to be put. Where the term concentrationis used, it refers to the concentration of the sulfonates with respectto the oil present unless some other meaning is obvious.

In treating crude petroleum sulfonates, various crude materials areencountered, some of which have been extracted from acid-treated oils asin the manufacture of white oils. These extracted crude sulfonatescommonly contain between 25% and 60% (usually about 40% or 50%) oil ofvarious lubricating viscosities, various sulfonate contents betweenabout 30% and about 6,0% soap including between about one-half per centand 3% green acid soaps, and from 4% to 12% (for example, 8%) ofsodiumpsulfate and sodium suliite of which the sulfate predominates.Where the crude sulfonate is a neutralized sulfonated oil, it willusually contain about 50% to 90% of oil neglecting water and saltspresent. The inorganic salt content of neutralized sulfonated oil willusually range from 0.75% to 4%. y

The sulfonates are commonly salts of the alkali metal sodium and arewater-soluble. They are to be purified to eliminate the green acidsoaps, the sultes and sulfates mentioned, the water, and any proportionof the oil which is not desired in the iinal product and which Will beordinarily referred to herein as excess oil. The green acid soaps are tobe removed because of their deleterious effects in the end products, andthe sulfates and sultes are to be removed because they interfere withthe emulsifying properties of the sodium sulfonate and constituteimpurities therein if permitted to remain. in addition, if theseinorganic sulfates and sultes are retained, they are converted intoinsoluble polyvalent-metal compounds in the conversion stage and in thecase of alkali earth metals and lead settle to the bottom of thetreating tank as a mud which, in the presence of the sulfonates, iscoated with considerable quantities of oil because of the wettingproperties of the sulfonates and presents here the problem of diflicultseparation or the element of'unnecessary loss of a substantialproportion of oil and sulfonate.

The present invention involves certain new discoveries that I have made.Thus, I have found that, at appropriate temperatures, I am able topurify crude, watersoluble, alkali-metal sulfonates before conversionYto the water-insoluble, polyvalent-metal forms by commingling them withcontrolled proportions of water and of an emulsion-breaking,oil-soluble, at least partially water-soluble organic liquid, theobjectionable inorganic salts and green acid sulfonates passing into awater layer which settles out as a brine upon standing. Such treatmentmay be effected with very large gallonage and is facilitated where thewater is present as a weak sodium chloride solution, for example a 5%solution. o .v

i have also discovered that excess .oil may be separated from thewater-soluble alkali-metal sulfonate by controlling the proportions ofwater and emulsion-breaking liquid respective to the soap-oil content ofthe crude sulfonate. Generally, by holding the proportion ofemulsion-breaking liquid constant at a low level between 5 and 25volumes (or up to 40 to 50 volumes) per 100 volumes of soap-oil mixture(reckoned together) in the crude stock and adding water in increasingamounts, first a brine phase appears which settles to the bottom and maybe drawn oi as indicated above. Further additions of water cause an oilphase to appear which rises to the top and is readily separated from thethen concentrated soap layer. This rejected oil phase contains only afraction of a percent of soap but Idoes contain a few percent of theemulsionbreaking liquid and water. The rejection of the excess oil isincreased as the proportion of either the emulsionbreaking liquid orwater, or both, is increased, and appears to be practically independentof whether or not the brine phase is removed as soon as it appears; butunless the brine phase is removed after appearing, it will go back intosolutionupon further addition of solvent and water.

The production of both a brine layer containing undesirable inorganicsalts together with green acid soaps and a rejected oil layer containingexcess oil can often be accomplished in one step by careful selection ofthe treating doses of water and emulsion-breaking liquid, respectively.However, for greatest flexibility and ease of operation by less skilledpersonnel, it is usually preferred to conduct the purification and oilseparation as separate steps, differing from each other mainly in theamount of water present. Reference to Fig. 2 will show for example that,with a given amount of the particular' emulsion-breaking liquid within asuitable range with respect to the oil-soap content of the stock, abrine layer will appear upon increasing the water present (curves B)before a rejected oil layer will appear (curves A).

However, continued increase of the water beyond a certain point causesthe brine layer to decrease and eventually disappear; whereas when thecritical amount of water has been reached to cause appearance of arejected oil phase, further additions of water cause increasing amountsof oil to be rejected and the total amount of oil rejected tendsultimately to approach asymptotically the total amountof oil present inthe stock. Likewise, at a given water content up to a certain point, theyield of brine phase increases slightly with solvent dosage, but beyondthis point increasing dosages of solvent result in decreasing yields ofbrine,rwhereas after the rejected oil layer appears, the yield ofrejected oil continues to increase with increasing dosages of solvent ata constant water dosage, at least within the range of solvent preferredin this invention. v i p l have also discovered that after the removalof any brine layer settling to the bottom and the separation of therejected oil which rises as a supernatant layer, the alkali-metal soapin the soap-oil concentrate layer which contains the water and theemulsion-breaking liquid, may be easily converted to water-insoluble,oil-soluble, polyvalent-metal soap by mixing therewith a Water solutionof a salt of an appropriate polyvalent. metal, the mixture beingallowedto stand'at appropriate temperatures for a moderate time whereupon sharpseparation results Y between the polyvalent-metal soap and oil layerandthe aqueous layer. j

It is apparent that the invention comprises a comkplete process whereb)I,the crude mahogany acid sulfonates aisles@ are (1) puried by removinginorganic salts/and green cid soaps in the form of all aqueous brine,(2) C911- centrated by rejecting and removing excess oil, and (3)converted to polyvalent-metal sulfonates. These three steps areefficiently controlled by the proper adjustment of three variables,namely variation of the proportion of water, as above indicated,employment of an appropriate proportion of emulsion-breaking liquid andoperation at a suitable temperature.

Generally temperature is not a critical variable; however, temperatures,may range in the neighborhood of 140 F. to 170 F. when the variousoperations are conducted batchwise, and 160 F. to 200V F., whenconducted inv a continuous manner, for each of the purification,concentration, and conversion steps, are conveniently employed. y

Efficient proportions of emulsion-breaking liquid ordinarily range fromabout 5 parts to about 30 parts for each 100 parts of soap-oil (reckonedtogether) in the crude sulfonate to be treated,

As to water contents, while different stocks have somewhat differentrequirements, as is always true in any type of treatment of petroleumfractions or derivatives, nevertheless, in general, approximately partsto 60 parts ot' Water (preferably largely sodium chloride solution), areeffective in the purification stage for each 100 parts of soap-oil(reckoned together) in the crude stock to remove objectionable inorganicsalts, sodium sulfate and sodium sulte, and the undesired green acidsulfonates. ln the concentration stage, additional water and/ oremulsion-breaking liquid is supplied if insuicient excess oil has beenrejected during the purification step. Ordinarily, 30 to 50 parts ofwater total per 100 parts of soap-oil (reckoned together) in the crudestock to be treated Vwill give suitable rejection of excess oil.

Additions of either water or the emulsion-breaking organic liquid orboth to a mixture whose composition is in the range for oil rejectionwill -disturb 4the solvency equilibrium and cause additional rejectionof oil into the supernatant layer. The resultant underlying concentratedsoap layer (soap ,Y oncentrated with respectto oil) may thus be made tocontain oil in that proportion desired in the final product.

l have discovered that instead of using.V practically pure water (citydrinking water), along with the emulsion-breaking liquid, to wash outwater-soluble impurities from a crude sodium sulfonate-oil mixture, Ican advantageously use an aqueous salt solution in many instances. Whereit is expected that purified sodium sullonate will subsequently be.converted to calcium, barium, or strontium, sulfonate, it is verydesirable Vto remove sulfates and sulfites as far as practical to .avoidformation of the water-insoluble sulfates and sultes of these polyvalentmetals during the conversion of the soap. The presence of anions whichdo not give water-insoluble salts with the polyvalent metals is notobjectionable from this standpoint, such anions being chlorides,nitrates, acetates, etc. Therefore, if the presence of these anions inthe wash water effects greater removal ofthe sodium sulfate and sultitein the brine layer duringthe purification step, their use is oftenjustified. in general, chlorides of the monovalent metals are preferred,especially sodiumtchloride because of both its efficiency and relativelylowcost. When using sodium chloride solution in place of water duringpurification, Vthe same behavior is obtained as is illustrated by thecurves in Fig. 2, exceptthat the amount of brine phase settling out foragiven dosage of solvent and water, respectively, is both larger involume and more concentrated in sulfates and sulfites.

lf a purified concentration alkali-metal sulfonate is desired as'the endproduct7 the concentrated soap layer is simply distilled to remove'waterand the emulsionbreaking organic liquid, and the resulting residue isIE- covered, with or without ,final ,Purification by filtering orcentrifuging while heated,

l0% solubility or miscibility in water. Y ing point, it is intended tosignify a boiling point below If .a Purified.Concentrated.polyvalent-metal ,Salton-atc is desired as the end product,the concentrated vsoap ,layer is reacted with an appropriateWater-soluble polyvalentmetal salt such,V as calcium chloride.4 Usuallythe polyvalent-metal salt is added in the form ofV a concentratedaqueous solution, but withtproper agitation the solid salt in the formof flakes, powder, or crystals, ,may be added directly to theconcentrated soap layer. On account of the presence of theemulsion-breaking organic liquid, the reacted mixture stratifiesreadily-intoV a converted soap layer, containing also the remaining oiland most of the emulsion-breaking organic liquid, and an aqueous phasecontaining by-product salts, excess-reagent salt, and a very smallproportion of emulsionbreaking organic liquid. The converted soap layeris separated and distilled or' otherwise suitably treated to recover theemulsion-breaking organic liquid and finally dehydrated and recovered asthe end product after filtering or centrifuging while heated.

While temperatures are not particularly critical, as mentioned before,nevertheless, at temperatures materially below F., viscosity conditionsbecome a consideration because they delay phase separation, land at lowtemperatures such as around 100 E, the separation of the various phasesmay be inconveniently slow. However, if the time element is of littleconsequence, temperatures may be used down to 100 F., for example,without difficulty. While temperatures :as high as 185 F. and up toabout 200 F. produce rapid settling, they, nevertheless, may complicatethe matter of maintaining adequate concentration of theemulsion-breaking liquid in batchwise operations. Therefore, atemperature of about F., or from about 140 F. Vto 170 F., has been foundto be a desirable optimum and representative of ya good compromisebetween speed of separation and settling of the layers and retention ofemulsion-breaking `liquid in the batches during such separation andsettling.

Discussion of preferred temperatures in continuous operations is givenbelow. L f

With respect to the emulsion-breaking liquid, (which is also oftenherein designated as the solvent for convenience), this maybe anyoil-soluble, at least partially water-soluble organic liquid describedbelow and consisting of carbon, hydrogen and oxygen, of suitably lowboiling'point to facilitate its removal :and recovery from the variousphases and of sufficiently low viscosity not to disturb seriously thevarious operations.v At least partially water-soluble signifies at leastabout 0,1% to By suitable boilthe decomposition point of the sulfonatesso that the diluent liquid may be eliminated from the product byvaporization. In general, this signifies a boiling point not materiallyin excess of 400 F., inasmuch .as the initial decomposition temperatureof a sulfonate such as calcium sulfonate may be in the neighborhood of450 F. to 500 F. However, higher boiling solvents can be recovcredbydistillation under vacuum.

This class of emulsion-breaking solvent liquids (which are often hereindesignated as solvents for convenience) is at present best.represented'by the polyoxyethers,

i. e.ethers .having more than one oxygen atom, one or more cfr-which maybe in hydroxyl groups or in ester linkages, and in which ethers theratio of carbon atoms to oxygen atoms is lapproximately 2:1 `asdetermined Vby the following formula:

yformula the total number of oxygen atoms, Y, includes Otherwiseexpressed,

Ethylene glycol dimethyl ether (dimethyl cellosolve) cHaoCzHioCHEthylene glycol monobutyl ether or hydroxy ethyl butyl etherr(butylcellosolve) p-DioX-ane (diethylene dioxide or glycol ethylene ether)OCH2CH2OCH2CH2 Diethylene glycol monobutyl ether (butyl carbitol)C4H9OC2H4OC2H4OH Diethylene glycol dimethyl ether (dimethyl carbitol)CHgoCzHtoCzHtoCH Ethylene glycol ethyl ether acetate (ethyl cellosolveacetate) C2H5OC2H4OCOCH3 Ethylene glycol methyl ether acetate (methylcello solve acetate) CH3OCzH4OCOCHs All the above compounds have acarbon to oxygen ratio of 2:1 with the exception of the last which has aratio of 5:3 or 1.6621.

The ether which is presently preferred is the ethylene glycol monobutylether (butyl cellosolve).

Having reference to the accompanying batch iiow diagram of Fig. l andalso to a particular crude alkalimetal sulfonate which is a neutralizedsulfonated oil as an example of various crude sulfonates which have beensuccessfullyv treated, a preferred method of procedure.

arcuate which embodies the various aspects of this invention Y is setout below. n Y

The foregoing crude alkali-metal (sodium) sulfonate contains about 7.5%water, 16% total sulfonates, 74.5% oil, and 3% inorganic salts. Theinorganic salts are principally sodium sulfate with a very minor portionof sodium sulte, both of which are to be removed by this method. Thetotal sulfonate content consists of 14.5% mahogany acid soap and 1.5%green acid soap. It is desired to remove the green acid soap withoutloss of mahogany acid soap.

taining 40% soap. It is further desired to convert any trace of sodiumsulfonate appearing in the removed oil to calcium sulfonate in orderthat the removed oil may be used in formulating engine oils, rustpreventive oils, etc.

Purification stage- To the particular starting material, abovedescribed, water is added in an amount equal to approximately 20% of thecrude stock, corresponding to 21.5% `based on the oil-soap content ofthe cruderstock. Preferably a 5% sodium chloride solution is employedbecause the sodium chloride serves efficiently to' displace the sodiumsulfate and the sodium sulte so that the latter salts will come out-in asettled brine layer. The less sodium chloride used, the'less eicientlyare the sultes and sulfates eliminated. While stronger concentra- Ationsof sodium chloride may be employed, 10% or 15% for example, to obtaingreater removal of sulfates and sulfites, theradditionalcost is usuallynot considered justified.y This isy particularly Ybecause the amountsyof sulrfates and sultes which are not removed by employment It isdesired also to remove excess oil and produce a concentrated calciumsulfonate conof 35% sodium chloride -solution in Ithe proper-dosage areinsuicient to detract seriously from the usefulness of the purifiedsodium sulfonate as such or as a raw mateterial for makingpolyvalent-metal sulfonate.

To the crude sulfonate stock there is also added, be-

tween about 20 parts and about 30 parts per 100 parts of stockof theselected emulsion-breaking organic liquid or solvent described, such asethylene lglycol monobutyl ether, based on -the crude stock. In usingthis or other indicated ether, theether is usually saturated with water,in which ease appropriate allowance is made for such water content ofthe ether in formulating the treatment of a batch of stock.

In a particular instance gallons of the described crude sodium sulfonatestock containing about 16% total soap and about 7.5% water were pumpedinto a treating tank in admixture with 20 gallons of Water and 20gallons of the mentioned ether as the emulsion-breaking liquid orsolvent. As is represented in the batch flow diagram of Fig. l, thesodium chloride solution and the solvent are introduced/by pumps intothe crude sulfonate stream on its way -to a heater 10 in which themaxture is heated to about 150 F. to 170 F. and from which it is passedinto a tank 12. When the entire batch is charged, it is agitated for 20to 50 minutes to insure equilibrium between all componen-ts.

The heated and agitated mixture in tank 12 is then allowed to stand andsettle for several hours, for example over night, or other appropriateperiod of time which may rangefrom four or live hours up to any otherdesired time. During this interval the temperature gradually drops withthis volume of material to about F., the temperature, however, being atall times adequately high to assure good separation of a water (brine)phase which settles out `in the bottom of the tank, as indicated, andcarries with it all objectionable proportions of green acid soaps,sodium suliite and sodium sulfate, and similar objectionable inorganicsalts. Not only do the sultes Aand sulfates separate in the lower brinelayer, but the greenacid sulfonates are also carried down in this brinelayer because apparently they are preferentially soluble in the water ofthe brine layer, whereas the mahogany Vacid sulfonates which remain inthe supernatant layer are preferentially soluble in the oil and in theoil-soluble solvent.

The temperature range of 140 F. to 150 F., above indicated, has thefurther advantage that the separation of solvent vapors is small. npractice such vapors as do accumulate in the top of the tank areconducted to a solvent recovery system.

After sufficient standing and settling, the separated brine layer iswithdrawn from the bottom of the tank. In the particular example abovegiven, the brine layer measured 14 gallons at about 140 F., and thesoapsolvent layer measured 58 gallons, there being 68 gallons of oilwhich was rejected. Preferably the with drawn brine isV passed to astill and the dissolved solvent driven o and recovered.

Concentration .Stugalf further concentration is desired, the abovedescribed soap layer containing the oil, solvent, and mahogany soap ispassed from the tank 12 fthrough a heater 14 and upon its way to theheater is mixed with a quantity of tap water and'/ or solvent sufficientto unbalance the previous solvent relationship between the oil, soap,and solvent so that upon further standing and settling any desiredproportion of the excess oil in the soap-ol-solvent layer is rejecteddepending on the amount ofy water and/or solvent added. In the specificinstance water equal to 20% of the original charge of crude stock wasintroduced. ln the heater la they. soap-oil solvent mixture with theadded water is raised to a temperature of about 150 to 170 F.

as before, and this mixture is their either returned to the tank 12 orpassed to another t'ank 15 as indicated in vthe Yafffelrsie '9 owdiagram, where it is agitated to insure` equilibrium being establishedagain.

In the tank 15, the 'heated mixture is again allowed to stand and settleover night, or for several hours, so that the oil rejected by reason ofthe change in the solvent relationship separates as a supernatant layerabove a soap-oil concentrate containing the solvent and the water. Inthe example described above,- where the crude stock contained' 74.5%oil, approximately 90% of the oil in -the crude stock was rejected intothe supernatant layer, while of the oil in the charge remained in theunderlying soap layer. In effect, oil. appears to be rejected under agiven set of conditions until the ratio of coap to oil in the soapcontaining phase satisfies the equilibrium requirements for that set ofconditions (apparently without regardl to the quantity of cil in theoriginal charge of stock). Obviously, if the proportion of oil to soapis already below the equilibrium requirements, no oil will be rejectedunder that particular set of conditions. As more water and solvent areadded, however, a point will be reached where oil will be rejected. Wehave thus been able to concentrate alkali sulfonate to a degree whereonly 22 parts of oil remained for each 78 parts of sulfonate.

Conversion stagev.-The aqueous soap concentrate (containing the solventand some oil) which settles out in the tank is next subjected totreatment to convert the alkali-metal, water-soluble, oil-soluble,mahogany sul fonate into a water-insoluble, oil-soluble,polyvalent-metal sulfonate, This is accomplished by passing `the settledlayer of the soap-oil concentrate from the bottom of the tank 1S to aheater 16 to restore its temperature, and by commingling thisconcentrate with a water solution of an appropriate polyvalent-metalsalt. Commonly, calcium sulfonates lare produced, land for this purposea 10% to 40% solution of calcium chloride in water is used, thissolution being comminglcd with the soap-oil concentrate as .it is passedtothe heater 416 whereby to raise the temperature of both the calciumchloride solution and the concentrate to about 150 F. lf the rejectedoil has been removed from the tank 15 (or tank 12) to some other tank,such as tank 18, the mixture heated in the heater 16 may be returned tothe tank 15 (or the tank 12) or it may be passed to a conversion -tank20. As bcfore, the heated mixture is allowed to stand and settle forseveral hours, or over night, whereby a water solution containing excesscalcium chloride and sodium chloride settles out -to leave a clear,supernatant layer of calcium sulfonate concentrate in oil together withthe bulk of the solvent and a limited amount of entrained'or dissolvedwater.

In operating with'the original 100 gallons of crude sulfonate of theabove example, the amount of calcium chloride used to convert themahoganyl sulfonate in the v concentrate was about` 30poundsfwhichwasdissolved in abouteightgallons of water.

In order to provide aconsistent control of the concen- `tratlon of thesulfonate in the" end product, it has been found both easy and desirable`to reject more oil thanv necessary during the rejection operation andthen add t back an appropriate amount of the same or another moredesirable oil at a later stage to regulate the soap concentration in thefinal product.` Where the concentrated sodium sulfonate is tobe'converted to a polyvalent metal sulfonate, the concentrationadjusting oil may be added before, during, or after the conversion -tothe polyvalentmetal sulfonate. In the above example a portion of therejected oil phase was pumped into the conversion tank 18 following thetransfer of the concentrated sodium sul- Vfonate phase to the conversiontank 20.

Normally, in the conversion stage it might be expected that, in view ofpast experiences, the calcium or other polyvalent-metal sulfonate formedin such concentrated oil solution would result in the production ot avery a few hours to yield an underlying brine layer of sodium Y chlorideand calcium chloride in water with a sharply delined supernatant layerof polyvalent-metal soap in concentrated condition in the oil present,together with the bulk of the emulsion-breaking liquid used and aproportionV of water which is readily removable` during a subsequentdehydration step. We have no particular theory regarding the action ofthe indicated class of organic compound- Apparently the function of theemulsion-breaking liquid, is not so much that of a selective solventasrthat of breaking up an otherwise stable oil-continuous emulsion, or,possibly that of preventing formation of such an emulsion.

'111e calcium soapoilsolvent layer is then passed to a still 22 todistill off the solvent, which is recovered and sent to storage, and todehydrate the oil-soap concentrate to yield a nished product which maybe placed in storage, as in a receptacle 24, either with or withoutfiltering or other further treatment.

inasmuch as the excess oil rejected in the concentration stage in tank15 may contain a very small amount of mahogany soap, this soap should beconverted into calcium or other polyvalent-metal soap. Therefore, suchoil, having been passed for .example to the tank 18 for treatment, isrecirculated through a heater 25 in admix ture with the excess calciumchloride in the water solution drawn from the conversion tank 20, andthe temperature again brought up to about F. to 170 F. The heatedmixture is allowed to stand in the tank 13 until the water solutionseparates in the bottom and leaves a supernatant oil layer containingthe small amount of resultant calcium sulfonate. Such oil, which iscommonly of lubricating viscosity, is useful in lubricating,rust-preventing, and other petroleum compositions and is thereforedehydrated and recovered as avaluable product.

By finishing the converted soap layer and the converted rejected oillayer separately by adding Ca( OH)2 (calcium hydroxide) to insurealkaline products, distilling to recover solvent and remove water,finally heating to approximately 300 F., and then filtering with the aidof a small amount of diatomaceous earth, a yield of alkaline calciumsulfonate concentrate having a sulfated ash value :of 7% to 8%"may beobtained, and a yield of by-productV (rejected) oil having a sulfatedash value of about 0.02% to 0.10% may be obtained.

Referring to various aspects of the above-described treatment, in thepurification step the dosages of water (or NaCl solution) andemulsion-breaking liquid are best selected with respect to each other.It is apparent from Fig. 2, that, for each solvent dosage in the rangeof 5% to 15% Vbased on the oil-soap content of the stock, there is anappropriate range of water content of the mix (the sum of boththe'vvater present in the stock and the water added) Vfor any givensolvent content. This appropriate water content of the mix will usuallybe found in the range of 10% to 60%.water based on the oil-soap contentof the stock. Furthermore, in the appropriatethe same extraction ofsalts and other impurities (such as Vgreen acid soap) as a butylCellosolve dosage of 2O parts and a total water content of 47.5 parts.In the first case the yield of brine layer was 8 partsas compared with22 parts in the second, but the brine inthe first case wasmore-concentrated. (Other crudesulfonates will have somewhat differentoptimum ranges but the appropriate range will be found within thegeneral order of magnitude indicated for the stock shown above.) Whilethe extraction of impuritiesiwas about the same in the two cases, thepurified soap layer amounted to 56 parts in the first case and 68 partsin the second case, the amount of rejected oil being 66 and 70 parts byvolume, respectively. VSometimes it isV preferable to avoid simultaneousrejection of oilalong with the brine, as for example in one method ofoperating a continuous extraction column, but in the batch method,simultaneous separation of oil is of little consequence, and the dosagesof solvent and water are chosen to give the optimum extraction of saltsand other water soluble impurities regardless of simultaneous rejectionof oil from the soap phase.

In the event sufficient oil is rejected under conditions of optimumextraction of Water soluble impurities, then subsequent rejection of oilis obviously unnecessary and the concentration step is thereforecompleted along with the purification. conditions chosen do not rejectthe desired proportion of oil, then the brine phase is removed andadditional water is then added to bring up the total water used(including water originally in the stock) to the place on the curvewhere the desired amount of oil is rejected. Instead of adding water,more solvent or both solvent and water,

lmay be added to cause additional rejection of oil. If the purificationand concentration are to be conducted separately, the brine settled inthe purification step should be removed before any appreciableadditional water or solvent is added, lest the brine redissolve in themix.

Often, it is desirable to have present at least enough solvent tosaturate or approximately saturate the water present, in order to getgood separation. This is true especially where high volume ratios ofwater (such as higher than the indicated 60% of Water based on theoil-sulfonate content) are used, inasmuch as such saturation provides agood means for solvent control.

Otherwise, good solvent contents are found in the range of 10% to 50% ofthe total water content, or within a range of about to 50% based on theoil-sulfonate content. The economically and operatively preferred range,if not the most efiicient range, is from to 40% ofthe solventjoremulsion-breaking liquid, based on the oil-sulfonate content.

ln the event the crude sulfonate as received contains too much water togive a brine phase upon the addition of the specified solvent, theexcess water is removed by evaporation substantially in toto or, ifdesired, until the amount remaining corresponds to the working range forthe usual solvent dosage of 10% to 35%. The evaporation may be bydistillation or by heating and air blowing. In general the mostsatisfactory procedure is to remove most of the water and then add backthe desired amount as the stock is processed in accordance with thisinvention.

ln purifying crude sulfonates containing a high ratio of soap to oil, ithas been found convenient and etiicient to add a substantial amount oflubricating oil to the stock or to the mix being treated for thetwo-fold purpose of reducing the viscosity and reducing the solventpower of the soap phase for water-soluble impurities. As long as the oiladded is or" suitable' quality,'this entails little or no hardshipbecause this amount of oil is easily rejected, after the removal of thebrine layer, by addition of water or solvent and thereby recovered. Inthis instance the rejected oil may be recycled without removal ofdissolved or entrained solvent and water.

in the foregoing example of a commercial operation of the process, themethod of treatment is batchwise foreach of the purification,concentration, and conversion ste s. in many instances, however,particularly where the demand for the finished sulfonate is steady andof sufficient magnitude, it is desirable to operate the process in acontinuous manner.

Fig. 3 illustrates'continuous operation of the process On the otherhand, if the purification Cit . 12 with single stage treatment `vby thereactants. Fig. .4 illustrates continuous operation of the process witheountercurrent flow of reactants. Many modifications and combinations ofthe steps will be readily apparent to those skilled in the art from thedisclosures contained herein. For example, multiple treatments may begiven at each step of the process of Fig. 3, when'necessary to obtaincomplete results. f

Referring to-Fig. 3, the crude sulfonate in a storage tank 31 is fed bya pump 32 at a controlled rate through a line 33 to the processingsystem. The emulsion-breaking liquid solvent specified herein is chargedat a controlled rate through a pump 34 into the line 33 through whichthe crude snlfonate is flowing. Water or aqueous sodium chloridesolution is chargedthrough a pump 3S at a controlled rate also into theline 33 through which the crude sulfonate and solvent are owing. Themixture of crude sulfonate, solvent and water flows into a mixer 36which is equipped with suitable agitators and baliies to insure chemicalequilibrium of the reactants and reaction products as they emerge fromthe top of the mixer 36 through a line 37 and ow into a settling vesselor puriier'38. In this vessel, the soda brine phase containing sodiumsulte, sodium sulfate and other water-soluble impurities, such as greenacid soap, settles to the bottom and the purified sulfonate rises to thetop. The settled soda brine is withdrawn through a valve 39 actuated asby a suitable liquid level control device (at the interface) in vessel3S and sent to a solvent recovery still where the solvent is recovered,and the brine is then discarded.

The purified sulfonate practically free of brine droplets overflows fromthe tank 38 to a line 40 through which it is forcedby a pump 41 into amixer 42. Water is charged by a pump 43 into the line 40 through whichthe purified sodium sulfonate is fiowing'. Mixer 42 is equipped withsuitable agitators and baffles to insure equilibrium between thereactants and reaction products by the time they emerge through an upperline 44 and fiow into a settling vessel or oil rejector 45. The mixtureentering the vessel --S stratifies into a concentrated soap and oillayer settling to the bottom and a rejected oil layer rising to the topand removed through an upper line 45a. The concentrated soap layer istransferred from the bottom of the vessel 45 through a lower line 6 by apump 47 and a valve 48 which are controlled by a suitable liquid leveldevice in the settling vessel 45. A relatively concentrated calciumchloride solution is charged by a pump #i9 into the line 46 throughwhich the concentrated sodium sulfonate is flowing, this stream passingto a converter or mixer 50 equipped with suitable agitators and bafilesto insure thorough equilibrium between the reactants and reactionproducts when the mixture emerges at the topthrough a line 51 by whichit is carried into converted concentrate settling vessel 52. The mixtureentering the settling vessel 52 stratifies into two layers; namely, (l)an aqueous phase containing sodium chloride formed by metathesis fromthe calcium'chloride, excess calcium chloride, and other water-solubleimpurities such as the last portions of green acidfsoaps, and (2) anoily phase consisting of oil, converted sulfonate, and the major portionof the solventearried through the process to this point.

The oily'phase rises to the top of the settling vessel 52 and overflowsthrough u line 53 from which it is charged by pump 53a to a solventrecovery still 54. A

slurry of calcium hydroxide in either oil, water, or calcium chloridesolution is prepared in an agitator and pumped via a line 55a and a pump56 into the line 53 carrying the converted soap layer to the solventrecovery still 54. In practice the still 54 is duplicated, one stillbeing used for distillation While the other is being charged, or theconverted soap layer supplied by the line 53 is accumulated in anintermediate storage tank (not shown) while a batch is being run down inthe still 54, or the still 54 may be lof the continuous type consistingof a tubular heater and fractionating tower. Either steam or vacuum orboth may be used in the still toaid removal of the last tracescf solventand water from the converted soap layer. The converted soap layer isinall, heated to a temperature in the neighborhood of 300 F. and thenfiltered in a filter press 57 and sent to storage 5S. To aid iiltrationof the dehydrated calcium soap concentrate, a small amount ofdiatomaceous earth (e. g. Supercel, Hyflo), such as 1% to 2% by weight,is added before filtration. The

solvent from the converted soap layer is recovered in apparatus 59 forreuse in the process. v

inasmuch as the process depends upon the presence of water in thevarious steps, it is usually unnecessary to remove the dissolved waterfrom the solvent recovered from any step in the process. The water layerfrom the condenser of the solvent recovery system is occasionally rerunto vconcentrate the solvent.

Since the rejected -oil layer rising in the settling and oil rejectingvessel i5 contains a small amountof sodium mahogany soap which should beconverted, such oil is passed by the line 45a from the vessel d5v to amixer 60 equipped with suitable agitators and battles to insureequilibrium between reactants and react-ion products. Since the bottomaqueous layer in the settling vessel S2, resulting from the reaction ofthe concentrated soda soap with calcium chloride solution, containsexcess calcium chloride, this brine layer also i-s pumped to the mixer60 for the purpose of reaction with the soda soap in the rejected oil.This transfer is made by way of a line 61, a valve 61a, and la pump 61hcontrolled by a suitable liquid level device (not shown) in Vthe vessel52. The brine from the line 61 is delivered to the line 45a throughwhich the rejected oil is being forcedto the mixer 60 by a pump 60a.Following reaction between calcium 'chloride and the sulfonate of therejected oil in the mixer 60, the reac-ted materials leave the mixer 60by a line 62 and tiow into a settling vessel 63 where stratificationoccurs to yield a calcium brine layer on the bottom and a convertedoillayer on top. The converted oil layer is delivered by a line 64 and apump 64a to a still 65 for recovery of contained solvent and dehydrationof the oil.V The calcium brine layer is withdrawn from the bottom of`the vessel 63 through suitable level contro-l valves and pumps (notshown) and is processed for recovery of dissolved solvent and thendiscarded. A small portion of this brine can be used in the agitator 55,desired, in making a calcium hydroxide slurry to be added either to theconcentrated soap layer being charged to the still 54 or to theconverted, rejected oil layer charged to the still 65. The convertedby-product oil layer, in which any trace of soap carried over from theconcentration of the soda soap in the settling and rejecting vessel 45has now been Aconverted in ythe vessel 63 to calcium soap, When beingprocessed in the still. 65 may contain a slurry of calcium hydroxidesuspended in oil or water or brine containing calcium chloride addedfromthe agitator S5, as above indicated, or from an agitator 66 by a pump 67via a line 68, to the charge going into the still 65. in this still,both dissolved solvent and water are removed by heating :to `atemperature in the neighborhood of 300 F..,with the use of vacuum orsteam. The liberated solvent is recoveredin appropri-V ate apparatus 69for Vreuse in the process. The dehydrated solvent-free oil is filteredand sent to storage 70 for use in blending lubricating oils, rustpreventives, and the like, or it may be further refined to produce whiteoils.

ln the operation illustrated in Fig. 3, the temperature is preferablyhigher than in the batch method illustrated in Figfl, to insureeiiicient operation of the continuous settling vessels; namely, in. theneighborhood of 160"4 F. to 200 F. als .previously indicated.Appropriate heaters (not shown) are employed in much the same way asshown in Fig. l. Care is taken to avoid loss of solvent by vaporization,even to the point of operating allY mixers and settlers under pressure.

.in the lower section ofthe column S2.

The higher boiling solventsof the disclosed class are often preferred inthe continuous method of .operating the'process at the highertemperature, because they are Fig. 4 illustrates a countercurrent,continuous operation of the process,vthe crude sulfonate in Vstoragetank 7i being fed by la pump '72 atia controlled rate through a line "i3tou the processing system. The emulsion-breaking' liquid'solventspecified herein is chart'ed at'a rcontrolled rate Vby a pump 74 intothe -line 73 through which 'the crudesulfonate Vis liowing. The mixtureof stock and solvent enters the iower portion of a countercurrentextraction column 75 while water or aqueous sodium chloride is chargedat a controlled rate by a pump 76 and a Vline '77 into the upper portionof the extraction column 75. As the mixture of stock and solvent worksits way up the column, the water or sodium chloride solution works itsway downward and extracts from the stock the water-soluble impuritiessuch as sodium sulfate, sodium sulte and the green acid soaps. The brinethus formed settles in the bottom of the column 75 and is withdrawnthrough a valve 7% which is ractuated by a suitable level control inthecolumn 75 and is sent toa still for recovery of the solvent dissolvedtherein. The extracted or puritied stock containing the bulk of thesolvent introduced into the stream of stock in the line 73, passes outof the top of the column '75 through a line 7'9 and is forced by a pumpif@ through a line 31 either directly into an oil rejection orextraction column 82 or via an agitator S3 by proper manipulation ofvalves 34, 85, and S6. Water is charged into the system at a controlledrate by a pump 83 through a line it? by opening a valve 90, and/ orIwater Vis charged at a controlled rate into the top section ofthecolumn S2 by a pump 91 via a valve 92 and a line 93. Water chargedthrough the line 89 mixes with the puried stock and solvent in the lineSi. This mixture may be thoroughly agitated by closing the valve tiltand openingthe valves'' and S6 and forcing the mixture through theagitator S3 which provides sulicient agitation to insureequilibriumbetween the reactants and the reaction products; this usually beingpreferred when water is introduced by the pump and line 35* into thestream being processed; Sometimes it is desirable Vto introduce all ofthe water via the `pump 9i and line 93 into the top section of thecolumn S2., in which case the stock iowing in the line $1 is made tobypass the agitator 33 by opening the valve S4 and ciosing the valves $5and 86. The water introduced into the top section of the extractioncolumn $2 via line 33 washes countercurrently 'the rejected oil which isrising upward in the column 2, and also causes rejection of oil from thepuriiied stock In other words, partial or fairly complete rejection ofoil may be accomplished by the water introduced along with the Vstockvia'the line Sl and agitator' S3, while any Waterintroduced into Ytheupper section of the column iZvvia the 'line 93 serves to wash out soapdissolved or entrained in the rejected oil rising from the bottom or thecolumn. --The soda soap solutionrnow concentrated with respect to oilsettles to the bottom of the column 82 and is removed via a valve 94 andaA pump '95 which are actuated bya suitable level control device (notshown) in the lowest section of the column S2. The concentrated sodasoap solution is forced .by the pump 95 Vvia a line 96 into the bottomsection of a conversion or extraction column 97, going through anagitator 9S or by-passing this agitator by proper operation of valves99, and 101. Aqueous calcium chloride solution of suitable concentrationis charged into the column 97 by a pump 102 via Ya line 103 into the topsection of the extraction column `anemie 97, or bya pump 104 into thebottom section of the column 97 in admixture with the concentrated soapstock moving in the line 96. If calcium chloride solution is introducedinto the line 96, it is desirable to agitate the resulting mixturethoroughly before it reaches the column 97 by sending it through theagitator 98 by opening the valves 100 and 101 and closing the valve 99.If a portion of the calcium chloride solution is premixed with the stockin the agitator 98 and introduced into the bottom section of the column97, via the line 96 along with the stock, any additional calciumchloride solution introduced by the pump 102 moves countercurrent to thereacted oily soap phase rising in the column 97 and serves to completethe conversion of sodium soap to calcium soap. The converted soap phasellows out the top of column 97 via a line 105 and a pump 106 and is sentto intermediate storage tank 107 whence it is sent to a still 108, forrecovery of solvent in apparatus 109, and dehydration before ltering.Lime or other reagents may be added to the stock in the tank 107 beforeit is charged to the still 108 by a pump 110. Diatomaceous earth whichserves as a filter aid is added before, during, or after thedistillation and dehydration. The rdehydrated concentrate is passedthrough a lter 111 and the finished calcium sulfonate concentrate issent to storage 112.

The spent or partially spent calcium chloride brine resulting from theconversion of the soda soap to calcium soap in the agitator 98 andconversion or extraction column 97, settles to the bottom of the column97, whence it iswithdrawn through a valve 113 and pump 114 and sent to astill for recovery of dissolved solvent.

The oil rejected in the rejection column 82 rises upward and settlespractically free of entrained water and soap in the top of the column.However it contains a very small proportion of dissolved mahogany soapwhich should be converted. Therefore, the rejected oil is passed fromthe top of the column 82 via a line 115 and a pump 116 into a treatingcolumny 118, and calcium chloride solution, which may conveniently bethe partially spent brine layer settling to the bottom of extractioncolumn 97, also is introduced into the top of column 118 via a pump 119and a line 120, or into the bottom of the column 118 via a pump 121 anda l-ine .122. Any calcium chloride solution introduced via pump 119 isbest mixed with the rejected oil phase owing in the line 115 by passingthe mixture through an agitator 123 before it goes into the treatingcolumn 118. The operation of the conversion of the small amount of 'sodasoap carried over in the by-product oil owing from the top of therejection column 82 is similar to the conf version of the concentratedsoda soap phasey settling to the bottom of the column 82 and convertedand separated in the column 97.

The converted, rejected oil in the column 118 rises to the top and issent via a pump 124 and a line '12411 to intermediate storage 125,whence it is charged by a pump 126 to a still 128 for solvent recoveryin apparatus 129 and for dehydration before iiltering. After passingthrough a filter, this converted, rejected oil is sent .to storage foruse as a lubricant, or in compounding rust preventives or lubricants, orthe like. The brine phase in the column 11S settles to the bottom and iswithdrawn via a valve 131 and a pump 132 which are controlled by asuitable liquid level device (not shown) in the lowest portion of thecolumn 118. This brine is distilled for solvent recovery and is iinallydiscarded.

It is to be understood that this process, whetherbatch or continuous, islalso applicable to the treatment of alkalimetal or ammoniumsulfonate-oil concentrates of commercewhich contain around to 60%sulfonates and 40% to 70% oil with impurities in the form of green acidsoaps, sulfates, sultes, and the like, although this process isparticularly adapted to the treatment ofV sulfonated oil containing theindicated lower soap contents.

-lt is also to be understood that where a reference to 1 i5 alkali-metalsulfonates is made in this specification and the claims the expressionis to be construed as including also the equivalent ammonium sulfonates.

. blended product.

`the product.

Additional data involving the treatment of crude sulfonate-oil stockwith Various solvents of the present class in various amounts ispresented in the following table:

Ether treatment-100 volumes of stock Separatlons, vols. Ether Vols.fWatcr,

vols.

Brine Soap Oil Butyl cellosolve 20 10 8 66 (i6 Do 20 20 l4 58 0S Do 808O 10 176 84 Methyl cellosolvw acetate. 40 40 20 1 70 90 Dimethylcellosol ve 40 40 43 59 7 8 Dlmethyl carbitoY' 40 40 G 98 76 Butylcarbito1" 4 0 40 18 80 82 Dioxane 40 40 20 70 7G 1 2 layers.

VWhile the puried polyvalent metal petroleum sulfonates or mahoganysoaps obtained in accordance with this invention are usually calciumproducts, the invention, nevertheless extends to the preparation ofother alkaline earth metal sulfonates, especially barium and strontiumsalts. These may be prepared with water-soluble salts of barium andstrontium as readily as the calcium product is produced. The process isalso applicable to the production of other Water-insoluble, oil solublesulfonates, and these may include the mahogany acid salts of aluminum,zinc, magnesium, lead, cobalt, nickel, and

, the like.

Concentrates of the above nature may be put to various uses. Forexample, the addition of 5% to 20% of the above concentrate to calcium,aluminum, barium, magnesium, zinc, and lithium base greases,respectively, has both imparted markedly improved anti-rustingproperties and reduced tendencies to bleeding or separation of the oilcontent of the greases :on standing.

Rust preventives constitute another important phase of use of thepresent product. These are obtained by diluting` the appropriatepolyvalent-metal sulfonate concentrate with appropriate carriers, suchas any mineral oil lubricating fraction suitable for the ultimate use ofCommonly, such dilution will yield a sulfonate content between about.05% and about 6% in the Ordinarily a satisfactory working proportion isabout 3% of sulfonate, or within a range of about 2% to about 4% Anotherimportant use of the puried, polyvalent-metal sulfonate of thisinvention is in connection with the production of lubricating oils forsevere service, internal combustion engines, such as aircraft and otherheavyduty engines, including diesel engines. Here the sulfonate may bepresent in proportion to impart rust-preventive characteristics =or forother purposes, including pron motion of detergent and wear-reducingcharacteristics. For these purposes, typical lubricating oils maycontain from about 0.5% to as much as 10%, for example 3%,

' of the purified alkaline earth metal sulfonates of this invention,together with such other additive constituents as may be deemeddesirable. Depending upon the ends sought, such other-'materials mayinclude sulfurized a1 cohols, sulfurized hydrocarbons, thiophosphates,zinc dithiophosphates, phenolic thioethers, phosphites, metalderivatives of these materials, various oil-soluble detergent soaps,such as the calcium soaps, and similar metal soaps of syntheticcarboxylic acids obtained from the oxidation of paraftinic hydrocarbons,alkyl phenols, pour point depressors, anti-oxidants, viscosity indeximprovers.

and kindred materials known in the lubricating industry.`

I have also found that the presence of 0.25% to 2% of octyl alcohol orother high molecular weight alcohol in the finished lubricant increasesVery greatly the effectiveness of the'sulfonateaddition in combatingcorrosion from hydrobromic acid. For example, the addition of 2.5%calcium sulfonate to a heavy-duty motor oil containing 0.75% calciumsoap of oxidized petroleum acids and 0.75% calcium salt of tertiary amylphenol sulde was suicient to protect the crankcase interior of enginesagainst rusting from moisture condensation, but was insuicient toprotect against dilute aqueous hydrobromic acid. The addition of 0.75%of octylalcohol (Z-ethylhexanol) to the foregoing oil containing 2;5%sulfonate, as described, gave perfect protection against hydrobromicacid corrosion.

While I have described the process as being applicable to petroleumsulfonates produced by sulfuric acid treatment of petroleum fractionsparticularly thosein the lubricating oil range, the process is alsoapplicable to sulfonates producedjsynthetically by sulfonation ofhydrocarbons or other compounds from coal tar products or any othersource. Also, the process'is applicable to sulfates (often calledsulfonates) produced b'y reacting sulfuric acid or sulfur trioxide withalcohols and/or unsaturated compounds belonging to the classes ofhydrocarbons, acids,` esters, ketonesgethers, glycerides, waxes, ctc.

Inasmuch as variations of the different features of the genericinvention herein disclosed will no doubt occur to those skilled in thisparticular art, it is intended to cover all modifications which fallwithin the scope of the patent claims. y

I claim as my invention:

l. The process of treating a material consisting of a major proportionof hydrocarbon oil containing alkali metal mahogany sulfonates,V alkalimetal green acid sulfonates and water-soluble inorganic sulfate andsulte, which comprises: forming a mixture consisting essentially of saidhydrocarbon oil, said alkali metal mahogany sulfonates, said alkalimetal green acid sulfonates, said Water-soluble inorganic sulfate andsulte, at least 10 parts by volume of water per 100 parts by volume ofsaid hydrocarbon oil and sulfonates and at least 5 parts by volume per100 parts by volume of said hydrocarbon oil and sulfonates of ahydrocarbon oil-soluble emulsionbreaking liquid selected from the classconsisting of ethylene glycol dimethyl ether, ethylene glycol monobutylether, p-dioxane, diethylene glycol monobutyl ether, diethylene glycoldimethyl ether, ethylene glycol ethyl ether acetate and ethylene glycolmethyl ether acetate, the amounts of said water and saidemulsion-breaking liquid being sufficient to produce three separablephases, a concentrated mahogany sulfonate phase containing hydrocarbonoil, water and emulsion-breaking liquid, a hydrocarbon oil phaserejected from said concentrated mahogany sulfonate phase and an aqueousphase containing alkali metal green acid sulfonates and water-solubleinorganic sulfate and sullite; and separating said three phases fromeach other.

2. 'I'he process as dened in claim 1 in which the temperature of saidhydrocarbon oil phase and said concentrated sulfonate phase during saidseparating is between 140 F. and 200 F. Y

3. The process as deiined in claim l in which the emulsion-breakingliquid is ethylene glycol monobutyl ether.

4. The process as defined in claim 1 in which the emulsion-breakingliquid is ethylene glycol ethyl ether acetate.

5. The process as dened in claim l in which the emulsion-breaking liquidis ethylene glycol dimethyl ether.

6. The process as dened in claim 1 in which a watersoluble polyvalentmetal salt is mixed with the separated concentrated mahogany sulfonatephase to convert the alkalipmetal mahogany sulfonate therein to apolyvalent "18 metal mahogany sulfonate and produce a'separable aquelousphase and a concentrated polyvalent metal mahogany sulfonate phasecontaining hydrocarbon oil and minor proportions of water andemulsion-breaking liquid and the separable aqueous phase is separatedfrom said concentrated polyvalent metal mahogany lsulfonate phase.

7. The process of treating a material consisting of a major proportionof hydrocarbon oil containing alkali metal mahogany sulfonates, alkalimetal green acid sulfonates and water-soluble inorganic sulfate andsulte, which comprises: forminga mixture consisting essentially of saidhydrocarbon oil, said alkali metal mahogany sulfonates, said alkalimetal green acid sulfonates, said watersoluble inorganic sulfate andsulte, sodium chlorideLat least 10 parts by volume of water per 100parts by' volume of said hydrocarbon oil and sulfonates and at least 5parts by volume per 100 parts by volume of said hydrocarbon oil andsulonates of a hydrocarbon oil-soluble emulsion-breaking liquid selectedfrom the class consisting of ethylene glycol dimethyl ether, ethyleneglycol monobutyl ether, p-dioxane, diethylene glycol monobutyl ether,diethylene glycol dimethyl ether, ethylene glycol ethyl ether acetateand ethylene glycol methyl ether acetate, the amounts of said water,said sodium chloride and said emulsion-breaking liquid being sucient toproduce three separable phases,A a concentrated mahogany sulfonate phasecontaining hydrocarbon oil, water and emulsion-breaking liquid, ahydrocarbon oil phase rejected from said concentrated mahogany sulfonatephase and an aqueous phase containing alkali metal green acidsulfonates, water-soluble inorganic sulfate and sulte and a majorproportion of saidl sodium chloride; and separating said three phasesfrom each other.

8. The process as dened in claim 7 inwhich a watersoluble polyvalentmetal salt is mixed with the separated concentrated mahogany sulfonatephase to convert the alkali metal mahogany sulfonate therein to apolyvalent metal 'mahogany sulfonat and produce a separable aqueousphase and a concentrated polyvalent metal mahogany sulfonate phasecontaining hydrocarbon oil and minor proportions of water andemulsion-breaking liquid and the separable aqueous phase is separatedfrom said concentrated polyvalent metal mahogany sulfonate phase.

9. The process of treating a material consisting of a major proportionof hydrocarbon oil containing alkali metal mahogany sulfonates, alkalimetal green acid sulfonates and water-soluble inorganic sulfate andsulte, which comprises: forming a mixture consisting essentially of saidhydrocarbon oil, said alkali metal mahogany sulfonates, said alkalimetal green acid sulfonates, said water-soluble inorganic sulfate andsuliite, at least l0 parts by volume of Water per parts by volume ofsaid hydrocarbon oil and sulfonates and at least 5 parts by volume per100 parts by volume of said hydrocarbon oil and sulfonates of ahydrocarbon oil-soluble emulsionbreaking liquid selected from the classconsisting of ethylene glycol dimethyl ether, ethylene glycol monobutylether, p-dioxane, diethylene glycol monobutyl ether, diethylene glycoldimethyl ether, ethylene glycol ethyl ether acetate and ethylene glycolmethyl ether acetate, the amounts of said water and saidemulsion-breaking liquid being sufficient to produce an aqueous phasecontaining alkali metal green acid sulfonates and watersoluble sulfate4and sullte, and a separable hydrocarbon oil-sulfonate phase containinghydrocarbon oil, water, emulsion-breaking liquid and alkali metalmahogany sulfonates; separating said hydrocarbon oil-sulfonate phasefrom said aqueous phase; mixing with the separated hydrocarbonoil-sulfonate phase an additional amount of a liquid selected from thegroup consisting of water, and said emulsion-breaking liquid, theamounts of said water and said emulsion-breaking liquid in the resultingmixture being suicicnt -to produce a concentrated mahogany sulfonatephase containing alkali metal mahogany sulfonates, hydrocarbon oil,water and emulsion-breaking liq- V19 uid and. a separable Ilztydrocarbonoil phase rejected from said concentrated mahogany sulfonate phase; andseparating said hydrocarbon oil phase fromv said concentrated mahoganysulfonate phase.

10. The process as defined in claim 9 in which the enliulsion-breakingliquid is ethylene glycol monobutyl et er.

11. The process as detined in claim 9 in which the emulsion-breakingliquid is ethylene glycol ethyl ether acetate.

l2. The process as defined in claim 9 in which the emulsion-breakingliquid is ethylene glycol dimethyl ether.

13. The process of treating a material consisting of a majorv proportionof hydrocarbon oil containing alkalil metal mahogany sulfonates, alkalimetalV green acid sulfonates and Water-soluble inorganic sulfate and,sultite, which comprises: forming a mixture consisting essentially ofsaid hydrocarbon oil, said alkali metal mahogany sulfonates, said alkalimetal green acid sulfonates, said` water-soluble inorganic sulfate andsuliite, sodium chloride, at least l0 parts by volume of Water per 100partsv by volume of said hydrocarbon oil and sulfonatesand. at least 5parts by volume per 100 parts by volume of said hydrocarbon oil andVsulfonates of a hydrocarbon oilsoluble, emulsionfbreaking liquidAselectedl from the class consisting of ethylene glycol dimethyl other,lethylene glycol monobutyl ether, p-dioxane, diethylene glycol monobutylether, diethylene glycol. dimethyl ether, ethylene glycol ethyl etheracetate. and ethylene. glycol methyl ether acetate, the amounts of saidwater, said` sodium chlorideV and said emulsion-breaking liquid beingsu'icient to produce an aqueous phase containing alkali metal green acidsulfonates, water-soluble sulfate and sultite and said sodium chloride,and a separable, hydrocarbon oil-sulfonate phase containing hydrocarbonoil, Water, emulsion-breaking liquid and alkali metal mahoganysulfonates; separating said hydrocarbon oil-sulfonate phase from saidaqueous phase; mixing with of a liquid selected `from the-groupconsisting Aof Water,

and said emulsion-breaking liquid; the amounts off'saidV Water; saidsodium chloride and said emulsion-breaking liquid in the resultingmixture being sufficient to produceV a concentrated mahogany sulfonatephase containing alkali metal mahogany sulfonates, hydrocarbon oil,water and emulsion-breaking liquid and a separable hydrocarbon oil phaserejected from said concentrated mahogany sulfonate phase; and separatingsaid hydrocarbon oil phase from said concentrated mahogany sulfonatephase.

14. The process as defined in claim 13 in which a water-solublepolyvalentv metal salt is mixed with the separated concentrated mahoganysultonate phase to convert the alkali metalmahogany sulfonate thereinto'a polyvalent metal mahogany sulfonate and produce a separable aqueousphase and a concentrated'y polyvalent metal mahogany sulfonate phasecontaining hydrocarbon oil and minorA proportions of water andemulsion-breaking liquid andtheseparable aqueous phase is separated?from said concentrated polyvalent metal mahogany sulfonatephase.

15. The process defined in: claim 13'- inwhich the emulsion-breakingliquid. ethylene glycol monobutyl ether.

1.6. The process defined in claim 13 in which the emulsion-breakingliquid is ethylene glycol ethyl ether acetate.

17. The process defined in claim 13 in which the emulsion-breakingliquid is ethylene glycol dimethyl ether.

References Cited in the tile, ofY this patent UNITED STATES PATENTS1,901,383' Voogt Mar. 14, 1933 2,084,506 Rosen June 22, 1937 2,168,315Blumer Aug. 8, 1939 2,522,212 Dammers Sept. 12', 195()

1. A PROCESS OF TREATING A MATERIAL CONSISTING OF A MAJOR PROPORTION OFHYROCARBON OIL CONTAINING ALKALI METAL MAHOGANY SULFONATES, ALKALI METALGREEN ACID SULFONATES AND WATER-SOLUBLE INORGANIC SULFATE AND SULFITEWHICH COMPRISES: FORMING A MIXTURE CONSISTING ESSENTIALLY OF SAIDHYDROCARBON OIL, SAID ALKALI METAL MAHOGANY SULFONATES, SAID ALKALIMETAL GREEN ACID SULFONATES, SAID WATER-SOLUBLE INORGANIC SULFATE ANDSULFITE, AT LEAST 10 PARTS BY VOLUME OF WATER PER 100 PARTS BY VOLUME OFSAID HYDROCARBON OIL AND SULFONATES AND AT LEAST 5 PARTS BY VOLUME PER100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES OF AHYDROCARBON OIL-SOLUBLE EMULSIONBREAKING LIQUID SELECTED FROM THE CLASSCONSISTING OF ETHYLENE GLYCOL DIMETHYL ETHER, ETHYLENE GLYCOL MONOBUTYLETHER, P-DIOXANE, DIETHYLENE GLYCOL MONOBUTYL ETHER, DIETHYLENE GLYCOLDIMETHYL EHTER, ETHYLENE GLYCOL ETHYL ETHER ACETATE AND ETHYLENE GLYCOLMETHYL ETHER ACETATE, THE AMOUNTS OF SAID WATER AND SAIDEMULSION-BREAKING LIQUID BEING SUFFICIENT TO PRODUCE THREE SEPARABLEPHASES, A CONCENTRATED MAHOGANY SULFONATE PHASE CONTAINING HYDROCARBONOIL, WATER AND EMULSION-BREAKING LIQUID, A HYDROCARBON OIL PHASEREJECTED FROM SAID CONCENTRATED MAHOGANY SULFONATE PHASE AND AN AQUEOUSPHASE CONTAINING ALKALI METAL GREEN ACID SULFONATES AND WATER-SOLUBLEINORGANIC SULFATE AND SULFITE; AND SEPARATING SAID THREE PHASES FROMEACH OTHER.